SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '879ae83f6ab830ac13336fb4fdcbf3945607f97456a6c68279df26117a586369' 
  AND token = 'UpsR2p1DIrKfbDeiPjn/0oFXgoevHMhm6Cs1/ob9fMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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