SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc19bb2c98ab99682e057938f1a2fcdc5cc990efb29d837ae33230d879272f1c' 
  AND token = 'NNYH/UsSlEOMiIsdpMSLLB8oKEhZwy8BiT4ej3/te9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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