SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6075ed126dc641874db7ab1b996be0f0aa838bce24776af77f8c37089f476583' 
  AND token = 'svFuXp+i7i7QYhl89DW5Hkz+sl3U+32r3oCkRS2TPqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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