SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2784547cd40349e9f85e8f0707f532fb3863bcc698eac5e62b1ada379dcf730' 
  AND token = 'DMXEMG4qdQiweIzp2WSaF8uvtTx5+5+bsQuFEijdBf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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