SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '92a844612d223ed4b43081856310142d6e2045ded58c8f6319626815be0d60d1' 
  AND token = 'A202Ve1z16RbMXAgoO3q1piQtz+sqZWXPnaz7TfKF0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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