SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fa0ed9956586ebf363a5b0ac06b83871187e7a244b67c8b79f6263c64dd606e' 
  AND token = '0/xzBpXDtE2xGWtIaS7Ki4Odiy4d0RfLeriBf4Pa+Ro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00075

JSON explain

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