SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c8f22de2bd63ee648cb1a7863f0432a0a627b2883000b6e5ca8fca75b41f5c2f' 
  AND token = 'ydo2lgVBrsslvwMc0Fh8TS8Xk794vD3pB/ehOjbB1N0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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