SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfcb944f2793060732cb992b2a60404b2f75195a51b1d17512187b14a6a409d9' 
  AND token = 'FKAmMxIdvoOQPABCvES2Wl2aosaXbWDFOpZO9Zj3cuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}