SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '495319cbd914e25952527b0b1b52ff7ace8d9df837f2d4e219833574da2b85d1' 
  AND token = 'kO7nGuXPPJTxikZ9AvyZ8Ahts9YNIHl/4LZm+Qx3M4s=' 
  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"
    }
  }
}