SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5214d7b9bfb168775796e3a0dc709feb4fccc873ed83b3b0dde72cd6354d6ac3' 
  AND token = 'W8/D8dLqgf34+Swv6INWs6kk9A0SFMlmWXdbORd9SFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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