SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '497f0fd451c2f97ee105e1d4236c999d36e10a1c37bcc49194e43821d42ec7d6' 
  AND token = 'nd7quzUsOmPZ8FZSOHYzxjUNVZzBw6eLxQA1Qg1Xybc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}