SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a049a92f640014332de9dcaeb831a0b6555fcc1555236e87da3faef1077f92df' 
  AND token = 'jCN1yZuHOgeDu1nummCewn9/IDt56wMjeYgKZr5AWas=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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