SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67c553a54023c65ffd3650fdbe286fdebc8f9179caa4aa343e90d3f27476470d' 
  AND token = 'fpbwvZWnNW4cUx1T/JFWhRVUnIA5pimkFK42mD8OM10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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