SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '491a454b3e604207d05b799979f9a180277ed05d3feb4c06e22b7483eb8ed5b1' 
  AND token = 'n20quS6GQ7IE8CpsvW5qF/jY0FqEmKzNWj1CW8Auhbo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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