SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ffcdd09df9574d2b04246fdc7c1214ef1693b53df72b55457b9f392bc94ff84' 
  AND token = 'P+KVoGJs55IXCA+KRLhw72ITEsotOMfGqQbsOefarRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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