SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afc48cb048247d253ac354a10054cf4a27a774721c020b23c9c9c80d14b1f08b' 
  AND token = 'Q/Ydu4SD1VQLAWBsH2hqR79Dim3/u2Wjg2nxbAZ3QfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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