SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '10202c4ed689ca3d99a8873d736938839d09baba8ec3af30c335c1de592dbce9' 
  AND token = 'FpsIAoi1nyrrvflB5uywdd0VyYHALfgfkImscIinfqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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