SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9b2c119e16a82943ec7391cbdd60743cf9a3154f43d29ce1cb099e1c853d5f6b' 
  AND token = 'GT4YwJZDYpzVSu0kZ3kMN5+zGgm+NTNvHfnoGtU4Yb0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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