SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a566c751bc578d76446d2b16a841d6ea4701ee02bc2dd897952a20b6d3fa304f' 
  AND token = 'WvmJ8QTUeGnw/LSTWK57HNwZuq8v1Gqew77knx8slhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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