SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd91dda343486b0c2683d71cddb3056841b4c8c24250a39637dcae66c8176261' 
  AND token = 'VgukXTG4sZOhmb76rrwyBzkdU8QjNeUDMNVosL1TwqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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