SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd13a148eaaa5f8cc881a4a0bdc46ddc88b125dd3c89d375afc49f84a87218d5' 
  AND token = 'Aa30Ux8wEkD0TjXBlNClpMjVPW4b8+Qvp8uuquGkd7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

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