SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'af31dfcf0c46c705ce27a92b1997b774e20578612f86a9155454f9cc7d2c8e81' 
  AND token = 'BpIs3tvxo+HuNy+2Qc/3KizkNRX28aydOxn3j/L/Jx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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