SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1783a72027b7dea1669906e943bec0af79c19d9821938f7967f296e06bde08a9' 
  AND token = 'ElFuge6l+3djaYsuPQK87hSrev6Po/SZPhXh1fK8t9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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