SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ef0aa449cf172fd7fdd38bc0a59330bf92bed3472663482de497002882fae1e' 
  AND token = 'A5TEkcsKiFvijPpTngpO+uSdod4Ygm/56AynYj6i7zI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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