SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65d19722861f29781cd4f6019c9ee75f545086ef39591ebd658c2972daf1944a' 
  AND token = 'qLhc6zGDttHOS+3E/TAf+YY+cUrOIPvo+NpJHuuXdmk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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