SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c54c18303bd9f8d46a59b068abcb0984a508095ce0df48f04b9589848b97e624' 
  AND token = 'zFX/KfffXgFe5G6QZnrzfe/uQm6EwEY0H2QPHMHm4E8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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