SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df3707592c05f275199ecc3a6e1922993fe75fe26ef5845ccab161fc5238860f' 
  AND token = 'AnuepvMQVE40Y7gfrXL1QWRQk/+6A6WcdbbJ9ddJWy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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