SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f23c2247b5bb6f3b880bc3dff0bd4cda39ff87f6e6fb86510121759d975d3445' 
  AND token = 'Mo7AIamwc9lAfDGLCIFgfhpHHqYOIKVYVdcSBxt0TVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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