SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a298c5675edb2f05f5ac9518a255713663aee68163d44cc6117ac0fad57bb9f' 
  AND token = 't/RJnxpL3TqPnuL0yd3ZJDfxgpzMS4bsmUaHYTkUB5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}