SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4362d1ac74df53ac0900d855617f1dd4e7579b87041f2eca1af3c014fc8bfae0' 
  AND token = '9/bHqWCr/CSHSTyZjVGyxqBoe6xEf4uu2SpGmhBPzqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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