SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe587b1541a3064f840ed28899501811d07e2e5588b99431463f9e22e0e65a90' 
  AND token = 'au/3XHXjjeujn0R8U+1WOA3pTEb8HHLxVH7UXIj8UM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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