SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9eb0b088607474e21311d4088fa54090b07b0e270445c747efc0962b3246fd4f' 
  AND token = 'mFzKq289QnKyimKVSCJsKJ46EY8B8BYLUzwzwvyPnLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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