SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '81ea9dbdbe0f142194c0cb6d78c8ce9070226706ef7d570b82ca61192a1d94ef' 
  AND token = 'gRDS0dF3IsG8Azseo1nfpOi+RHj3cAGnHR1401I2OII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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