SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '683f6ade2e2b12101c0befb8271a5858cfff9c8aad9878e30b34c6f1a8fec30f' 
  AND token = 'KJYUiSVhK/Ndh4jz5lmI59gq8foKIL63kQCX9KIdX58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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