SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e086117195c45da3d75f646c70adecd2d0ccb1bdee8f21cf5aabd1eb9937b65' 
  AND token = 'R4aZml8r/UpCZKxFY/ImfzZAN0IgvNugK0ShKgFFjHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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