SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93f2af2d93cfa109552265c9402279f97c7d18dc229cda698e40bb9463142d13' 
  AND token = 'UFxOcwwdvejCLzNLmOrcqTDSUI2nFbPTpv7cQ22QEF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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