SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b5c8e851e59c48232e32d40e957f7b7aefb37f0a3607b42dd15651c9ef68dba' 
  AND token = 'EvphA5fnqGvZhtXj3RU3LhsYqGQpvaQq2gwO+VOhekY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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