SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '142292e8ec64babec3b0e14b9773021ef83369e0c12d090aafc23915112ef5a7' 
  AND token = 'jKxTJen5cBDMoGQcZqdh7H23xhUz0WT8NLxtDdf/E3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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