SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44fb9a3d3871b91a1df365d211fb915693f0b34f81a5ae014e62661caeb57b32' 
  AND token = '+Irg/2gXtgbJbq7GPwe/gOJAmSL2U0Blz3phoQhGONc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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