SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c7502051cce7236f2a6c0218837d8e2041a9b4b98554a453359498e499d0a5bb' 
  AND token = '81CXHTIuCRT/hlTlFk8DlFYeuvQLAeWt7YDC0W5TBoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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