SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b5a4824768da37e39c19a6165a79391e7f875fa960c22bd11a59f7372404ec38' 
  AND token = 'oaj3ERmYS6Whm91El+FbGAKUIYVUeNC0ELc+hwCP2h8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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