SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '435aadbee0065ca232c104bb79c09b8d90a81a8b7a5772a6a343781bc5c17086' 
  AND token = 'jeJ6ds1r1SmODC3z+jDo08gjexLCBsEhxj6uCfQf3Ho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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