SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec24b0034cf109cac965641f4b5872477745f6ca213251019a76dccf2e827952' 
  AND token = 'pvjQsDlkFf7oxw/pi9NQgi46o0qzupugPKnBC8uMd18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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