SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17c425824a57f5257538037ea12730c785c0058c4cf723da378244c2ded9484c' 
  AND token = '0ZiGxHPefrTjL8oOMp7dBlrd/Z+u26MuwBTiwzVKBvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}