SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04964d4515e22fb2fa0db2f4cbc8377a64af5b6ce581d2813c4a9e48ba3fb3c5' 
  AND token = 'h3N/iW3zTP4gPxxLZVOApj+uj7xjhgKMe70LosBMRKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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