SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c02b953798d51669f861d26c9d1c7978690218ca71831c278570687d72c74e86' 
  AND token = 'EpvcRlgNnQ5rSPgtJv8j56YeU1y+tUwBDezIhsXiYNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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