SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '770e4d15191d6a710d56b415f8370c127ca936d24cdf59786ff56d0c1a1fdb23' 
  AND token = '1/+4vjMgQSiKrYg+c1XwkGCeethf4HTd1vjzl/JU6+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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