SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a2469b126668442dd59b14efa77fcafd8f144f923ad6c6d43b87efc2f316cfa' 
  AND token = 'pqsmxgpIL8US3pufENfYyyxZyv7OpALftLpG1M4LI/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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