SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59ae48bf4959b1d365129dee0f6f864daf5f096072267e87c01d488699e32343' 
  AND token = 'BTVPpCJCIojDSgMiJrKx/ip8RgNCAI26iYI6+nmRqgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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