SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df2aea20af3c0594cfd86b779025cfe282184da7dff2959402a26ffc54371965' 
  AND token = 'aco7pzM2Yt3szpIXVoFuf0keq76H9MoDcQO7lrgo0zQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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