SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '71303e902eafdbafc4e24ca1bd45c47e8c2e379b1ed90e824a5579822f781bf4' 
  AND token = '/qZPfGK+u8YjtltwZ3YRLq7uBHbjHfRN2ihI6sn7R1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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