SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '906bdf362babfe6b126393b8dd0869b019ba67966301d075dfddd392f46afe37' 
  AND token = 'JpPTJ7Zu7BG8eHltIQ4zGzWRm3bZgiLPpBzb/JxJhSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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