SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c02244ae229060b1e42b35134e7568298d1cb142026ae2790beb339ed348f252' 
  AND token = 'SaFdn70YTyYNmBlvLGR15WuTY28bhsm0ERiXRlClSWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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