SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43e200d064a8313f45f047e441bb363a58ae0032390dd3b0430d0a7fc73d1bdc' 
  AND token = 'U1Wf5QMfk5vagYETrhOR1vg8x7dbOXF9LtDz1dFEFX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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