SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c4b0a9a55258075cac04cf2443bc7c0c28a3c6d8c5ca5701fb726c9bb578e352' 
  AND token = 'xH4jw8f8kuS767pXyI1PU3c6RQMz2NLVIdmIaCXHYUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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