SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7e9b863ba90b0a428d372fa7f3622a8ea44446d67ac2d4533d922f42899a7734' 
  AND token = 'Lh1CpwXWAAtAvzbXOhrEe0oNdSAqtvZhneu969zE+Kg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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