SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f8f4c0cb5ecc3c7068e930547d1c42b428a493e4e8d2d7e464dc266624d09d9' 
  AND token = 'htckCcFX8pCIucsQVcMNVcTTlqm/ztIITy95uTHpPLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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