SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ff4c65947808f11701989141ae48dfab24bb5bf7f2fb4aed8dcd7e4a052b37a' 
  AND token = '0+2MteTtZNQhRFeFkgKy0jDUqoiM+gsNc/RIfSEBU/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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