SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96d18b6dbbf8615fd56d48af773d6e8bee82d70cf47d03be3c4f25c37416e993' 
  AND token = 'dOg7XUv+X/ZjoAJEBaQqnOfRgc3Fy2v+MzCdepZI++c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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