SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d990811af31df971fb024ad0adc2d847d60267bdd5b44b77046d32dcf5e6a00' 
  AND token = 'Pfcbx5jGdaqn14lStjGJhZJehWkWquJuTxYHoffkPE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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