SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a17c1983248aa69c62af1dfef44cfa507fdbb84ff160d879a5213258b250ea5f' 
  AND token = '3rypKX0ZLXnlVoylFx1ifSGRcptsINlsU9vBzjeUv4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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