SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbf5edfc094cc784c9e1111529d9715d3750a8dcc734d8503113e0801d0d9402' 
  AND token = 'WESBEPtUCO6y7KfCTcjorQSarhGxvHyEKlWwQHB4MxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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