SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba8ec4025fa6eb8da7b21845f4032e8a1e45b89822b012d70f6c9d4c2cb2c122' 
  AND token = 'h38T53tCnIaaDMBUCkz5Evfg8TDSymSRy4Au4WUpDvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}